• Defined Intensity Stressor Simulation (DISS);
  • S-IgA reactivity;
  • acute stress;
  • increased workload;
  • perceived workload demands


Previous work suggests that secretory immunoglobulin-A (S-IgA) reactivity is inversely related to the perceived demands of the stressor. The Defined Intensity Stressor Simulation (DISS) comprises eight stressor modules, and allows for the manipulation of stress either through increasing the number of modules, or increasing the workload of the modules. The current study assessed the effect of increasing the workload of four modules upon S-IgA reactivity and perceived demands. Participants (N = 14) attended three sessions on consecutive days where they provided a timed saliva sample immediately before and after 5 min on the DISS at low, medium and high workload. Following each session participants recorded their perceptions of the task with regard to workload and levels of stress and arousal. Perceived workload and stress, but not arousal, increased in accordance with increases in workload, however, differential S-IgA reactivity was observed. Low workload resulted in a slight increase in S-IgA secretion; medium workload elicited significant up-regulation, while down-regulation of S-IgA occurred following high workload. As DISS is analogous to a variety of working environments it is suggested that the observed S-IgA reactivity is indicative of how individuals react to multi-tasking environments when faced with increases in objective or perceived workload demands. As S-IgA levels are related to protection from illness, down-regulation of S-IgA in those who perceive greater demands may lead to greater vulnerability to ill-health. Copyright © 2005 John Wiley & Sons, Ltd.